Hi sir,
You have neither mentioned your category here nor your home state.
So, assuming you are from General Category. Here are the probable colleges that your son would get CSE/ EE/ ECE in:-
 CSE:-
1) NIT Andhra Pradesh
2) NIT Uttarakhand
3) NIT Agartala
4) Newer IIITs like Kota, Sonepat, Trichy, Kancheepuram, Sri city
5) NIT Meghalaya

 ECE:-
1) BIT Mesra
2) IIEST Shibpur
3) NIT Goa
4) NIT Hamirpur
5) NIT Raipur
6) IIIT Kancheepuram

 EEE:-
1) BIT Mesra
2) NIT Goa
3) NIT Andhra Pradesh
4) NIT Uttarakhand
5) NIT Jamshedpur

You can use our college predictor to check your chances to get into different NITs, IIITs and GFTIs:-
https://engineering.careers360.com/jee-main-college-predictor

Hope it would help.
Thank You.